Deaeration and purification of anionic detergent compositions



Sept. 13, 1960 R. P. DAVIS 2,952,638

DEAERATION AND PURIFICATION OF ANIONIC DETERGENT COMPOSITIONS Filed Aug. 5, 1956 O a. fir m'br 05ertflarals n. 40M111 v- 6063M die/x2496 Patented Sept. 13, 1960 DEAERATION AND PURIFICATION OF ANIONIC DETERGENT COMPOSITIONS Robert I. Davis, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Aug. 3, 1956, Scr. No. 602,046

11 Claims. (Cl. 252-138) This invention relates to detergent compositions, and more particularly to a chemical process for deaerating detergent composition slurries from which a high density spray dried detergent composition can be produced.

There are many factors which contribute to the bulk density of products obtained by spray drying detergent composition slurries. Among these factors are the composition and physical state of the slurry, the type of air flow in the spray drying tower (counter-current air flow resulting in a higher density product than is obtainable by concurrent air flow), nozzle particle size, tower height, and the number of British thermal units (B.t.u.) supplied per pound of water in the slurry.

In addition to the above factors, it is known that finely dispersed air in detergent composition slurries reduces the bulk density of granules produced by spray drying such slurrics. It has been a common practice in the detergent industry to blow air into crutcher mixtures in order to obtain low density products. When a high bulk density product is desired it is advantageous to remove the air which is normally entrained in detergent composition slurries. Frequently this entrained air will con stitute to of the volume of a slurry. Mechanical means for removal of this air at sub-atmospheric pressures are well known to the art. However, the initial cost and maintenance cost of the equipment necessary to achieve this mechanical deaeration is a material factor limiting the use of such equipment. The chemical deaeration techniques of the present invention involve inexpensive and practical means for liberation of the entrained air from the detergent slurry upon the addition of chemical compounds to the slurry.

It is an object of this invention to provide inexpensive and practical means for deaeration of detergent slurries. It is a further object to provide a means for chemical deaeration of dryable detergent slurries, thereby making it possible to produce a high bulk density spray dried detergent composition. It is a further object to provide, as additives for slUrrie-s containing anionic sulfate and sulfonate detergents materials which effect chemical deaeration of such slurries and which, in addition, contribute valuable performance characteristics to the finished product.

These and other objects, which will be readily apparent, are achieved by the present invention, a detailed description of which follows.

I have discovered that the addition of certain nonionic polyether detergents to slurries containing sulfate and sulfonate anionic synthetic organic detergents and inorganic salts such as sodium sulfate and water-soluble alkali metal silicates effect a material and rapid reduction in the amount of entrained air in the slurry when the slurry is agitated, and that these chemically deacrated detergent slurries can be spray dried by conventional techniques to form a granular product having a desirable high product density.

The present invention is based on the observation that the nonionic component (nonionic compound or mixture of nonionic compounds) causes a separation of slurry, which contains sulfate and/or sullonate anionic synthetic organic detergents, and inorganic salts such as sodium sulfate and water-soluble alkali metal silicates, into two distinct phases, viz. a low viscosity continuous lye phase which contains the inorganic materials and a discontinuous sopc phase which contains the organic constituents of the slurry. The word sope is used herein to designate one or more synthetic organic detergents. The physical state of the separated slurry is apparent from the accompanying photograph (Figure l), which shows a continuous lye phase (light colored area) completely surrounding the darker colored sopc masses. It is believed that the air which was initially entrained in the slurry coalesces in the low viscosity lye phase to form relatively large bubbles which in turn rise to the surface by channeling through the low viscosity continuous lye phase, and that agitation of the slurry results in a dispersal of the discontinuous sope phase, thereby facilitating the escape of the air. It has been observed that as bubbles of air visibly escape from the slurry upon the addition of the nonionic detergent, accompanied by agitation, the volume of the slurry correspondingly decreases.

The degree of agitation necessary for deaeration can be obtained in mixing vessels of the types which are usually employed for mixing moderately viscous liquids. For examples, a bafllcd mixing vessel having a diameter of 30 inches and depth of 27 inches and equipped with a 15 inch turbine type agitator running at from 200 to 600 revolutions per minute has been found to be satisfactory for deaeration of a 400 pound detergent composition slurry. The moderate degree of agitation provided by this mixing vessel is sufiicient to cause dispersal of the discontinuous sope phase but not so drastic as to pull air into the slurry. A mixing vessel of this construction was employed in Examples I, I], and III, which follow.

Figure 2 is a photomicrograph of an anionic sulfonate detergent paste which is commonly used in the preparation of detergent compositions. Air bubbles are visibly dispersed throughout and entrapped within the homo geneous paste. in the normal spray drying operation these bubbles would tend to cause the formation of a low bulk density granular product. The addition of silicate starts to break the tight emulsion as shown by the lines of lye phase in Figure 3, but very little air is released from the emulsion at this point. The addition of nonionic detergent grains out the slurry and results in the formation of a continuous lye phase and a discontinuous sope phase (Figure 1). At this point the slurry actually appears to be boiling. The air removal is usually not instantaneous and generally about 1 to 5 minutes of moderate agitation of the mixture are allotted for it to take place.

Detergent composition slurries such as set forth in Example I, which follows, normally have a density of about 0.9 to 1.1 and such slurries can be spray dried to form granules which have a bulk density on the order of about 0.29 to 0.35. A completely dcaerated slurry such as this will have a density of about 1.35. The chemical deaeration resulting from the addition of silicate and nonionic detergent to a detergent slurry having a density of about 0.9 to 1.1 increases the density of the slurry to about 1.25 to 1.3 and this increased density slurry can be spray dried by conventional techniques to form granules having a bulk density of about 0.41 to 0.44.

Detergent composition slurries, such as set forth in Example I, which have been built with about 18 parts of sodium tripolyphosphate, have a density comparable to that of unbuilt slurries, i.e. about 0.9 to 1.1. Such slurries can be spray dried to a bulk density of about 0.31 to 0.39. However, when the slurry is chemically deacrated and the tripolyphosphate is subsequently incorporated therein with a minimum of agitation, a spray dried product having a maximum bulk density of from about 0.49 to 0.51 can be obtained.

As is well known in the art heavy duty detergent compositions will result from the combination of synthetic anionic sulfate and sulfonate detergents and from about 1 to about 5 parts of alkali metal tripolyphosphate, for example, those described in Byerly, U.S.P. 2,486,921 and Strain U.S.P. 2,486,922. It is often desirable to incorporate into such heavy duty detergent compositions a material which will inhibit the corrosion of aluminum, and water-soluble alkali metal silicates are among the most satisfactory of the known aluminum corrosion inhibitors. It is therefore apparent that the processes of the present invention are particularly well adapted to the manufacture of heavy duty detergent compositions. The tripolyphosphate, however, is advantageously added to the slurry subsequent to the addition of the nonionic detergent and after deaeration has occurred. If desired, a part of the tripolyphosphate may be mechanically mixed in with the spray dried product obtained from a deaerated slurry; detergent compositions having very high bulk densities, e.g. over 0.6, can be obtained by this technique.

The nonionic compounds, which effect the phase change essential for chemical deaeration of an agitated slurry containing anionic sulfate or sulfonate synthetic detergents and inorganic salts according to the present invention, may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. As those versed in the art are Well aware, the length of the hydrophilic or polyoxyalkylene radical required for condensation with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well known class of nonionics is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule, of course, exhibits water insolubility. Its molecular Weight is of the order of 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole. Liquid products are obtained up to the point where polyethylene content is about 50% of the total weight of the com densation product. Further increase in the relative content of polyoxycthylene to hydrophobic portion renders the final product wax-like or solid in consistency.

The molecular weights of Pluronic L61, L64, and F68, which find particular utility in the practice of the present invention are approximately 2000, 3000, and 8000 respectively.

Suitable nonionics also include the polyethylene oxide condensates of alkyl phenols. These include the condensation products of alkyl phenols having about 6 to about 12 carbon atoms, either straight chain or branch chain, in the alkyl group with ethylene oxide in amount equal to approximately to approximately 30 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, di-isobutylene, octane, or nonane, for example. Compounds of this nature are commercially available on the market and include, for example, Igepal CO-730 and Igepal CO-SSO which are understood to be nonyl phenol polyethylene oxide condensates having respectively, on the average, 15 and 30 moles of ethylene oxide per mole of nonyl phenol.

Further suitable nonionics may be derived by the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. Here again, a series of compounds may be produccd, depending on the desired balance between hydrophobic and hydrophilic elements. In the present instance, compounds (molecular weight from about 5000 to about 11,000) of about 40% to about polyoxyethylene content and resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction products of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2500 to 3000, are suitable. This class of compounds is made commercially available under the trade name of Tetronics.

Other satisfactory nonionics include the condensation products of aliphatic alcohols having from about 8 to about 18 carbon atoms, either straight chain or branch chain, with ethylene oxide in amount equal to approximately 10 to approximately 30 moles of ethylene oxide per mole of alcohol. The alcohols may be derived from the higher alcohols produced by the reduction of tallow or coconut oil, for example. A coconut alcohol ethylene oxide condensate having approximately 15 moles of ethylene oxide per mole of coconut alcohol and an average molecular weight of about 800 has been found to be particularly satisfactory.

Thus, the products which find use in the present invention have an overall molecular weight within the range of about 800 to about 11,000.

The preferred nonionics employed in the practice of the present invention, alone or in admixture, are those which possess a hydrophilic polyoxyethylene radical in combination with a hydrophobic base consisting of the reaction product of an excess of propylene oxide and ethylene diamine.

The anioinic synthetic, to which reference is made and which is a constituent of the dense heavy duty or unbuilt detergent granules which can be produced by the practice of the present invention, is generally referred to as a water-soluble salt of an organic sulfuric reaction product having in its molecular structure an alkyl radical having from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. Important examples of the anionic synthetics which form an active part in the chemical deaeration techniques of the present invention are the sodium or potassium alkyl benzene sulfonates, especially those of the types described in U.S.P. 2,220,- 099 and 2,477,383 in which the alkyl groups contain from about 9 to 15 carbon atoms; sodium alkyl glyceryl ether sulfonates, especially those others of higher alcohols from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g. tallow or coconut oil alcohols) and about 3 moles of ethylene oxide; sodium alkyl sulfates obtained from the mixed higher alcohols produced by the reduction of coconut oil or tallow; and others known in the art, a number being specifically set forth in the Byerly and Strain patents.

In many of the spray dried detergent compositions which can be made according to the present invention miscellaneous ingredients including coloring agents, fluorescent dyes, perfumes, carboxymethylcellulose, sodium carbonate and other alkaline salts, and other materials well known as constituents in detergent compositions can be present.

In general, detergent composition slurries which can be deaerated according to this invention contain from about 40% to 60% of Water, from about 10% to 40% of anionic detergent, from about 5% to 25% of sodium sulfate, the weight ratio of sodium sulfate to anionic detergent being from about 1:7 to about 1:1, from about 5% to 15% of sodium silicate solids, and from about 1% to 4% of the nonionic compound. The use of amounts f the nonionic compound in excess of about 4% frequently results in the formation of a continuous sope phase, and no dcaeration occurs. All of the above percentages are by weight, based on the slurry.

Particularly excellent results have been achieved when the detergent composition slurry contained from 40% to 60% of water, from 15% to 20% of anionic detergent, from 15% to 20% of sodium sulfate, the weight ratio of sodium sulfate to anionic detergent being about 1:1, from 6% to 12% of sodium silicate and about 2% of the nonionic compounds. These percentages are also by weight, based on the slurry.

Although any of. the commercially available sodium silicate solutions having an Si0 /Na O ratio of from about 1:1 to about 3:1 is suitable for use in the practice of this invention, the preferred SiO /Na O ratio range is 1.511 to 20:1.

The following examples will serve to describe the invention with greater particularity.

Example I A slurry was formed in the following manner. To a paste consisting of 73.6 parts of a mixture of 23.5% sodium alkyl benzene sulfonate (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene) 56% water, 20% of sodium sulfate and 0.5% of miscellaneous ingredients, including carboxyrnethylcellulose, a tarnish inhibitor, and a fluorescent brightening agent, were added in succession 24.2 parts of sodium silicate (having a solids content of 45% and a ratio of SiO /Na O of 2:1) and 2.2 parts of Pluronic F68 (the condensation product of ethylene oxide with a polyoxypropylene base having a molecular Weight of about 1500 to about 1800, the condensation product having a molecular weight of about 8000).

This slurry was mixed with moderate agitation at a temperature of 160 F., for about 3 minutes, during which time it was readily apparent both from the visible turbulence and the decrease in volume of the slurry that a considerable volume of air was being evolved. Slurries such as this, prior to deaeration, have a density on the Order of about 0.9 to about 1.1 and will spray dry to give a product having a bulk density of from about 0.29 to 0.35. After completion of dcaeration, at which time the density will have increased to as high as about 1.25 to 1.30, these slurries can be spray dried to give a product having a bulk density of about 0.41 to about 0.44.

Similar results were obtained from a procedure corresponding to the above except that Igepal CO730 (a nonyl phenol ethylene oxide condensate having on the average 15 moles of ethylene oxide per mole of nonyl phenol) was substituted for Pluronic F68.

Following the procedure of Example I comparable results were obtained by substitution of the Pluronic F68 with an alkyl ethylene oxide condensate wherein the alkyl radical was derived from alcohols produced by the reduction of coconut oil fatty acids having from to 14 carbon atoms, said condensate having an average molecular weight of about 800.

Example II To a paste consisting of 40 parts of a mixture of 10% sodium alkyl benzene sulfonate (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene), 12% of sodium alkyl sulfate (the alkyl groups being derived from higher alcohols produced by the reduction of tallow), 55% Water, 22.5% of sodium sulfate and 0.5% of miscellaneous ingredients including carboxymethylcellulose, a tarnish inhibitor, and a fluorescent brightening agent, is added in succession 16 parts of sodium silicate (having a solids content of 45% and a ratio of SiO :Na O of 2:1), and 2 parts of Tetronic 707 (a commercially available nonionic condensation product understood to have a molecular weight of about 11,000,

being obtained by the condensation of ethylene oxide with a hydrophobic base resulting from the condensation of propylene oxide with ethylene diamine, said base having molecular weight of the order of 2500 to 3000, and the ethylene oxide content being about 70-79%.

The slurry thus formed is dcacrated with moderate agitation at a temperature of F. for about 2 minutes. Upon spray drying this slurry will produce granules having a bulk density of about 0.41 to 0.44.

Similar results can be obtained when Pluronic F68 (as described in Example I) is substituted for Tetronic 707.

Example III This example includes a comparison of otherwise comparable deaerated and undeaerated detergent composition slurries and demonstrates the elfect which chemical deaeration has on the bulk density of a spray dried built detergent composition.

To a paste consisting of 230 parts of a mixture of 24.55% sodium alkyl benzene sulfonate (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene) 59.5% water, 15.45% of sodium sulfate and 0.5% of miscellaneous ingredients including carboxymethylcellulose, a tarnish inhibitor, and a fluorescent brightening agent were added 81 parts of sodium silicate (having a solids content of 45% and a ratio of SiO :Na O of 1.6:1). The slurry thus formed had a density of 0985. On the addition of 11 parts of Hyfac 431" (a commercial fatty acid mixture derived from bydrogenated marine oil and reported to contain 8% myristic, 29% palmitic, 18% stearic, 26% arachidic, 17% behenic, and 2% oleic acids) the density became 0.97. Upon the addition of 21 parts of sodium sulfate and 56 parts of sodium tripolyphosphate the density changed to 0.99. Upon spray drying in a tower 10 feet in diameter having a 40 feet high straight sidewall and using countercurrent air flow, the nozzle temperature being F., the inlet air temperature being 415 F., and the exhaust air temperature being 194 F., a granular product containing 6% by weight of water and having a bulk den sity of 0.36 was obtained.

To demonstrate the ellect or": chemical deaeration a comparable procedure was followed with the exception that 7 parts of Pluronic F68 replaced 7 parts of the sodium sulfate.

To a paste consisting of 230 parts of a mixture of 24.55% alkyl benzene sulfonate (the alkyl radical averaging about 12 carbon atoms and being derived from polypropylene) 59.5% water, 15.45% of sodium sulfate and 0.5% of miscellaneous ingredients including perfume, a tarnish inhibitor, and a fluorescent brightening agent were added in succession 81 parts of sodium silicate (haw ing a solids content of 45% and a ratio of SiO :Na of 16:1). The slurry thus formed had a product density of 1.005. 7 parts of Pluronic F68 was added and the slurry was mixed with moderate agitation at a temperature of 160 F. for about three minutes, during which time a considerable amount of air was evolved. The density of the slurry increased to 1.225. Upon the addition of 11 parts of Hyfac 431 the density changed to 1.15, and the addition of 14 parts of sodium sulfate and 56 parts of sodium tripolyphosphate, accompanied by very mild agitation, raised the density to 1.30. This slurry was then spray dried under essentially the same conditions that were used for the undeaerated slurry and a product having a Water content of 6% by weight and a bulk density of 0.47 was obtained.

While the foregoing examples employ alkyl benzene sulfonatc type synthetic detergents having from 9 to 15 carbon atoms, averaging about 12 carbon atoms, in the alkyl radical, or such alkyl benzene sulfonate detergents in admixture with alkyl sulfates of the type derived from the sulfation of higher alcohols produced by the reduction of tallow; other sulfate or sulfonate synthetic detergents well known in the art can be substituted therefor with good results, alone or in admixture, in these examples.

The discovery that the addition of a minor amount of a nonionic detergent to a homogeneous anionic synthetic organic dctergent-water-electrolyte system will cause a separation of the system into two distinct phases, viz. sope phase containing the detergents and a lye phase containing the greater part of the electrolyte, has utility for purposes other than those purposes hereinbefore described. For example, this discovery may be utilized to obtain purified anionic synthetic detergents from mixtures of said anionic synthetic detergents and the sodium sulfate which is formed in the manufacture of the anionic detergents. It is difficult and expensive to separate electrolyte from anionic synthetic organic detergent by conventional techniques. By this invention sope and lye phases can be separated from each other, as by centrifugatio-n, to yield a lye phase consisting of water and a greater part of the electrolyte originally present in the slurry and a sope phase rich in anionic detergent and low in electrolyte.

What is claimed is:

1. In the process of making a high density spray dried detergent composition from a homogeneous fluid slurry initially containing entrained air, and containing from about 40% to 60% of water, from about 10% to 40% of at least one water-soluble alkali metal salt of an anionic organic sulfuric reaction product having in its molecular structure an alkyl radical having from 8 to 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, the said salt having pronounced detergent power in aqueous solution, and from about to 25% of sodium sulfate, the weight ratio of sodium sulfate to said anionic product being fro-m 1:7 to 1:1, and from about 5% to 15% of sodium silicate having an SiO :Na O ratio of from about 1:1 to about 3:1, the steps of (1) causing the homogeneous slurry to separate into a continuous lye phase which contains the inorganic materials of the slurry and a discontinuous phase which contains the organic constituents of the slurry by adding from about 1% to about 4% of at least one nonionic detergent constituted of a water solubilizing polyoxyethylene group in chemical combination with an organic hydrophobic compound selected from the group consisting of polyoxypropylene, alkyl phenol in which the alkyl group contains from about 6 to about 12 carbon atoms, the reaction product of an excess of propylene oxide and ethylene diamine, and aliphatic alcohols having from about 8 to about 18 carbon atoms, said non-ionic detergent having a molecular weight of from about 800 to about 11,000, (2) agitating said slurry, and (3) separating entrained air from the slurry, all percentages being by weight of the slurry after the addition of the nonionic detergent.

2. In the process of making a high density, spray dried detergent composition from a homogeneous fluid slurry initially containing entrained air and containing from about 40% to 60% of water, from about 10% to 40% of at least one water-soluble alkali metal salt of an anionic organic sulfuric reaction product having in its molecular structure an alkyl radical having from 8 to 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, the said salt having pronounced detergent power in aqueous solution, and from about 5% to 25% of sodium sulfate, the weight ratio of sodium sulfate to said anionic product being from 1:7 to 1:1, and from about 5% to about of sodium silicate having an SiO :Na O ratio of from 1.5:1 to :1 the steps of (l) causing the homogeneous slurry to separate into a continuous lye phase which contains the inorganic materials of the slurry and a discontinuous phase which contains the organic constituents of the slurry by adding from about 1% to about 4% of at least one nonionic detergent constituted of a water solubilizing polyoxyethylene group in chemical combination organic hydrophobic compound selected from the group consisting of polyoxypropylene, alkyl phenol in which the alkyl group contains from about 6 to about 12 carbon atoms, the reaction product of an excess of propylene oxide and ethylene diamine, and aliphatic alcohols having from about 8 to about 18 carbon atoms, said nonionic detergent having a molecular weight of from about 800 to about 11,000, (2) agitating said slurry, and (3) separating entrained air from the slurry, all percentages being by weight of the slurry after the addition of the nonionic detergent.

3. The process of claim 2 in which the nonionic detergent is a nonyl phenol po-lyoxyethylene ether having on the average from about 15 to about 30 moles of ethylene oxide per mole of nonyl phenol.

4. The process of claim 2 in which the nonionic detergent is a polyoxyethylene condensation product with a polyoxypropylene base, said polyoxypropylene base having a molecular weight from about 1500 to about 1800 and the said condensation product having an overall molecular weight from about 2000 to about 8000.

5. The process of claim 2 in which the nonionic detergent is a polyoxy-ethylene condensation product with a hydrophobic base constituted of the reaction product of ethylene diamine and propylene oxide, said base having a molecular weight of from about 2500 to about 3000 and said nonionic compound having an overall molecular weight of from about 5000 to about 11,000.

6. The process of claim 2 in which the nonionic detergent is a polyoxyethylene condensation product with the higher alcohols produced by the reduction of coconut oil and said nonionic compound has an average molecular weight of about 800.

7. The process of claim 2 wherein subsequent to the separation of entrained air from the slurry a watersoluble alkali metal tripolyphosphate salt is added to the slurry with incorporation of a minimum amount of air into the slurry.

8. In the process of making a high density, spray dried detergent composition from a homogeneous fiuid slurry initially containing entrained air and containing from 40% to 60% of water, from 15% to 20% of at least one water-soluble alkali metal salt of an anionic organic sulfuric reaction product selected from the group consisting of alkyl benzene sulfonate in which the alkyl radical has an average of about 12 carbon atoms and alkyl sulfate in which the alkyl group is derived from the higher alcohols produced by the reduction of tallow, the said salts having pronounced detergent power in aqueous solution, and from 15 to 20% of sodium sulfate, the weight ratio of sodium sulfate to said anionic product being about 1:1, and from 6% to 10% of sodium silicate having an SlOgZNE O ratio of 1.5 :1 to 2.011, the steps of (1) causing the homogeneous slurry to separate into a continuous lye phase which contains the inorganic materials of the slurry and a discontinuous phase which contains the organic constituents of the slurry by adding about 2% of at least one nonionic detergent constituted of a water solubilizing polyoxyethylene group in chemical combination with an organic hydrophobic compound selected from the group consisting of polyoxypropylene, alkyl phenol in which the alkyl group contains from about 6 to about 12 carbon atoms, the reaction product of an excess of propylene oxide and ethylene diamine, and aliphatic alcohols having from about 8 to about 18 carbon atoms, said nonionic detergent having a molecular weight of from about 800 to about 11,000 (2) agitating said slurry, and (3) separating entrained air from the slurry, all percentages being by weight of the slurry after the addition of the nonionic detergent.

9. The process of claim 8 in which the nonionic detergent is a polyoxyethylene condensation product with a hydrophobic base constituted of the reaction product ,Of ethylene diamine and propylene oxide, said base having a molecular weight of about 3000 and said nonionic compound having an overall weight of about 11,000.

10. The process of claim 8 wherein subsequent to the separation of entrained air from the slurry a water-soluble alkali metal tripolyphosphate salt is added to the slurry with incorporation of a minimum amount of air into the slurry.

11. In the process of separating the components of a homogeneous fluid slurry containing from about 40% to 60% of Water, from about 10% to 40% of at least one water-soluble alkali metal salt of an anionic organic sulfuric reaction product having in its molecular structure an alkyl radical having from 8 to 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, the said salt having pronounced detergent power in aqueous solution, from about 5% to 15% of sodium silicate having an SiO :Na O ratio of from about 1:1 to about 3:1, and from about 5% to 25% sodium sulfate, the weight ratio of sodium sulfate to said anionic product being from 1:7 to 1:1, the steps of (1) causing the homogeneous slurry to separate into a low viscosity continuous lye phase which contains the inorganic materials of the slurry and a discontinuous phase which contains the organic constituents of the slurry by adding from about 1% to about 4% of at least one nonionic detergent constituted of a Water solubilizing polyoxyethylene group in chemical combination with an organic hydrophobic compound selected from the group consisting of polyoxypropylene, alkyl phenol in which the alkyl group contains from about 6 to about 12 carbon atoms, the reaction product of an excess of propylene oxide and ethylene diamine, and aliphatic alcohols having from 8 to about 18 carbon atoms, said nonionic detergent having a molecular weight of from about 800 to about 11,000, and (2) separating the phases from each other, all percentages being by weight of the slurry after the addition of the nonionic detergent.

References Cited in the file of this patent UNITED STATES PATENTS 2,213,477 SteindOrff Sept. 3, 1940 2,515,577 Waldeck July 18, 1950 2,606,156 Davis Aug. 5, 1952 2,742,436 Jenkins Apr. 17, 1956 

1. IN THE PROCESS OF MAKING A HIGH DENSITY SPRAY DRIED DETERGENT COMPOSITION FROM A HOMOGENEOUS FLUID SLURRY INTIALLY CONTAINING ENTRAINED AIR, AND CONTAINING FROM ABOUT 40% TO 60% OF WATER, FROM ABOUT 10% TO 40% OF AT LEAST ONE WATER-SOLUBLE ALKALI METAL SALT OF AN ANIONIC ORGANIC SULFURIC REACTION PRODUCT HAVING IN ITS MOLECULAR STRUCTURE AN ALKYL RADICAL HAVING FROM 8 TO 22 CARBON ATOMS AND A RADICAL SELECTED FROM THE GROUP CONSISTING OF SULFONIC ACID AND SULFURIC ACID ESTER RADICALS, THE SAID SALT HAVING PRONOUNCED DETERGENT POWER IN AQUEOUS SOLUTION, AND FROM ABOUT 5% TO 25% OF SODIUM SULFATE, THE WEIGHT RATIO OF SODIUM SULFATE TO SAID ANIONIC PRODUCT BEING FROM 1:7 TO 1:1, AND FROM ABOUT 5% TO 15% OF SODIUM SILICATE HAVING A SIO2:NA2O RATIO OF FROM ABOUT 1:1 TO ABOUT 3:1, THE STEPS OF (1) CAUSING THE HOMOGENEOUS SLURRY TO SEPARATE INTO A CONTINUOUS LYE PHASE WHICH CONTAINS THE INORGANIC MATERIALS OF THE SLURRY AND A DISCONTINUOUS PHASE WHICH CONTAINS THE ORGANIC CONSTITUENTS OF THE SLURRY BY ADDING FROM ABOUT 1% TO ABOUT 4% OF AT LEAST ONE NONIONIC DETERGENT CONSITUTED OF A WATER SOLUBILIZING POLYOXYETHYLENE GROUP IN CHEMICAL COMBINATION WITH AN ORGANIC HYDROPHOBIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF POLYOXYPROPYLENE, ALKYL PHENOL IN WHICH THE ALKYL GROUP CONTAINS FROM ABOUT 6 TO ABOUT 12 CARBON ATOMS, THE REACTION PRODUCT OF AN EXCESS OF PROPYLENE OXIDE AND ETHYLENE DIAMINE, AND ALIPHATIC ALCOHOLS HAVING FROM ABOUT 8 TO ABOUT 18 CARBON ATOMS, SAID NON-IONIC DETERGENT HAVING A MOLECULAR WEIGHT OF FROM ABOUT 800 TO ABOUT 11,000, (2) AGITATING SAID SLURRY, AND (3) SEPARATING ENTRAINED AIR FROM THE SLURRY, ALL PERCENTAGES BEING BY WEIGHT OF THE SLURRY AFTER THE ADDITION OF THE NONIONIC DETERGENT. 